The long term lot has the little push carts that you can rent for a couple bucks. You can then wheel your luggage from the car to the building that has the monorail. The building has elevators too, so getting to the platform is easy. Monorail takes you directly to any of the terminals and you can take the cart and luggage on to the monorail and leave the cart at the terminal.
However, with parking now $18 a day in long term, you may want to look into off airport options if it's a long trip.
The long term lot has the